Abstract
AIM: To evaluate the significance of transforming growth factor beta (TGF beta) expression, in correlation with histopathological parameters, at the front of invasion in T1 colorectal cancer (CRC) and presence of metastases. METHODS: TGF beta immunohistochemical expression was studied in 34 specimens of colorectal adenocarcinomas (pT1). A three-step avidin-biotinylated immuno-peroxidase (ABCu-NCL) staining technique was performed on 4-mum paraffin-embedded tissue sections with a monoclonal antibody to TGF beta (Novocastra, NCL-TGFB, clone TGFB 17, dilution 1:40). RESULTS: Seventeen (50%) out of 34 lesions were positive for TGF beta expression. The TGF beta-positive rate in patients with vascular invasion was significantly higher than in those without vascular invasion (11/14 cases, P<0.01, P = 0.005). The TGF beta-positive rate was observed in 91.7% of patients with presence of tumor budding at the front of invasion (11/12 cases, P<0.01, P = 0.0003). A statistically significant correlation was found between the presence of lymph node metastases and positive expression of TGF beta (14/16 cases, P<0.01, P = 0.0001). We also observed that the TGF beta-positive rates in groups with distant and non-distant metastases were 92.8% and 20% respectively, and a significant correlation between TGF beta expression and distant metastasis was shown (P<0.01, P = 0.00003). CONCLUSION: The evaluation of TGF beta expression of protein in association with histological parameters can be used as a parameter of the aggressiveness of pT1 CRC.